The We Made You rapper said he saw lots of documentaries on notorious murderers while preparing to write his latest album Relapse.
He said: "I did find myself watching a lot of documentaries on serial killers. I've always been intrigued by them and watching movies like that, and I found that going back through my DVD collection and watching movies about killers sparked something in me.
"The way a serial killer's mind works, just the psychology of them, is pretty f***ing crazy. I was definitely inspired by that."
Eminem - real name Marshall Mathers - also admitted his last record, 2004s Encore, wasn't his best work. He added: "It feels a little too self-loathing to me. When I go back and listen to it - it just feels like I'm p***ing and moaning about whatever. It sounds like in my head I feel like I have all these things to p**s and moan about.
"Maybe I did, maybe I didn't, I don't know, but to actually bring that kind of shit to the forefront like that, I just don't agree with it. I guess to me now it feels like I beat up the subject of what was me. That's what that record's overall theme feels like."
Eminem's latest album, Relapse, comes out on May 19.